/*_############################################################################
  _## 
  _##  md5c.cpp  
  _##
  _##  SNMP++ v3.3
  _##  -----------------------------------------------
  _##  Copyright (c) 2001-2013 Jochen Katz, Frank Fock
  _##
  _##  This software is based on SNMP++2.6 from Hewlett Packard:
  _##  
  _##    Copyright (c) 1996
  _##    Hewlett-Packard Company
  _##  
  _##  ATTENTION: USE OF THIS SOFTWARE IS SUBJECT TO THE FOLLOWING TERMS.
  _##  Permission to use, copy, modify, distribute and/or sell this software 
  _##  and/or its documentation is hereby granted without fee. User agrees 
  _##  to display the above copyright notice and this license notice in all 
  _##  copies of the software and any documentation of the software. User 
  _##  agrees to assume all liability for the use of the software; 
  _##  Hewlett-Packard and Jochen Katz make no representations about the 
  _##  suitability of this software for any purpose. It is provided 
  _##  "AS-IS" without warranty of any kind, either express or implied. User 
  _##  hereby grants a royalty-free license to any and all derivatives based
  _##  upon this software code base. 
  _##  
  _##########################################################################*/
char md5c_cpp_version[]="#(@) SNMP++ $Id: md5c.cpp 2361 2013-05-09 22:15:06Z katz $";
/* MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm */

/* Copyright (C) 1991, RSA Data Security, Inc. All rights reserved.

   License to copy and use this software is granted provided that it
   is identified as the "RSA Data Security, Inc. MD5 Message-Digest
   Algorithm" in all material mentioning or referencing this software
   or this function.

   License is also granted to make and use derivative works provided
   that such works are identified as "derived from the RSA Data
   Security, Inc. MD5 Message-Digest Algorithm" in all material
   mentioning or referencing the derived work.

   RSA Data Security, Inc. makes no representations concerning either
   the merchantability of this software or the suitability of this
   software for any particular purpose. It is provided "as is"
   without express or implied warranty of any kind.

   These notices must be retained in any copies of any part of this
   documentation and/or software.
 */

#include <libsnmp.h>

#include "snmp_pp/md5.h"

#if !defined(_USE_LIBTOMCRYPT) && !defined(_USE_OPENSSL)

#ifdef __cplusplus
extern "C" {
#endif

#ifdef SNMP_PP_NAMESPACE
namespace Snmp_pp {
#endif

/* Constants for MD5Transform routine.
 */
#define S11 7
#define S12 12
#define S13 17
#define S14 22
#define S21 5
#define S22 9
#define S23 14
#define S24 20
#define S31 4
#define S32 11
#define S33 16
#define S34 23
#define S41 6
#define S42 10
#define S43 15
#define S44 21

static void MD5Transform PROTO_LIST ((UINT4 [4], const unsigned char [64]));
static void Encode PROTO_LIST ((unsigned char *, UINT4 *, unsigned int));
static void Decode PROTO_LIST ((UINT4 *, const unsigned char *, unsigned int));
static void MD5_memcpy PROTO_LIST ((POINTER, POINTER, unsigned int));
static void MD5_memset PROTO_LIST ((POINTER, int, unsigned int));

static unsigned char PADDING[64] = {
  0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

/* F, G, H and I are basic MD5 functions.
 */
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define I(x, y, z) ((y) ^ ((x) | (~z)))

/* ROTATE_LEFT rotates x left n bits.
 */
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))

/* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
   Rotation is separate from addition to prevent recomputation.
 */
#define FF(a, b, c, d, x, s, ac) { \
    (a) += F ((b), (c), (d)) + (x) + (UINT4)(ac); \
    (a) = ROTATE_LEFT ((a), (s)); \
    (a) += (b); \
  }
#define GG(a, b, c, d, x, s, ac) { \
    (a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); \
    (a) = ROTATE_LEFT ((a), (s)); \
    (a) += (b); \
  }
#define HH(a, b, c, d, x, s, ac) { \
    (a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); \
    (a) = ROTATE_LEFT ((a), (s)); \
    (a) += (b); \
  }
#define II(a, b, c, d, x, s, ac) { \
    (a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); \
    (a) = ROTATE_LEFT ((a), (s)); \
    (a) += (b); \
  }

/* MD5 initialization. Begins an MD5 operation, writing a new context.
 */
void MD5Init (MD5_CTX *context)
{
  context->count[0] = context->count[1] = 0;

  /* Load magic initialization constants.
   */
  context->state[0] = 0x67452301;
  context->state[1] = 0xefcdab89;
  context->state[2] = 0x98badcfe;
  context->state[3] = 0x10325476;
}

/* MD5 block update operation. Continues an MD5 message-digest operation,
     processing another message block, and updating the context.
 */
void MD5Update (MD5_CTX *context,                /* context */
		const unsigned char *input,      /* input block */
		const unsigned int inputLen)     /* length of input block */
{
  unsigned int i, index, partLen;

  /* Compute number of bytes mod 64 */
  index = (unsigned int)((context->count[0] >> 3) & 0x3F);

  /* Update number of bits */
  if ((context->count[0] += ((UINT4)inputLen << 3)) < ((UINT4)inputLen << 3))
    context->count[1]++;
  context->count[1] += ((UINT4)inputLen >> 29);

  partLen = 64 - index;

  /* Transform as many times as possible.
   */
  if (inputLen >= partLen) {
    MD5_memcpy ((POINTER)&context->buffer[index], (POINTER)input, partLen);
    MD5Transform (context->state, context->buffer);

    for (i = partLen; i + 63 < inputLen; i += 64)
      MD5Transform (context->state, &input[i]);

    index = 0;
  }
  else
    i = 0;

  /* Buffer remaining input */
  MD5_memcpy
    ((POINTER)&context->buffer[index], (POINTER)&input[i], inputLen-i);
}

/* MD5 finalization. Ends an MD5 message-digest operation, writing the
     the message digest and zeroizing the context.
 */
void MD5Final (
unsigned char digest[16],                                 /* message digest */
MD5_CTX *context)                                                /* context */
{
  unsigned char bits[8];
  unsigned int index, padLen;

  /* Save number of bits */
  Encode (bits, context->count, 8);

  /* Pad out to 56 mod 64.
   */
  index = (unsigned int)((context->count[0] >> 3) & 0x3f);
  padLen = (index < 56) ? (56 - index) : (120 - index);
  MD5Update (context, PADDING, padLen);

  /* Append length (before padding) */
  MD5Update (context, bits, 8);

  /* Store state in digest */
  Encode (digest, context->state, 16);

  /* Zeroize sensitive information.
   */
  MD5_memset ((POINTER)context, 0, sizeof (*context));
}

/* MD5 basic transformation. Transforms state based on block.
 */
static void MD5Transform (
UINT4 state[4],
const unsigned char block[64])
{
  UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];

  Decode (x, block, 64);

  /* Round 1 */
  FF ( a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
  FF ( d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
  FF ( c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
  FF ( b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
  FF ( a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
  FF ( d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
  FF ( c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
  FF ( b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
  FF ( a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
  FF ( d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
  FF ( c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
  FF ( b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
  FF ( a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
  FF ( d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
  FF ( c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
  FF ( b, c, d, a, x[15], S14, 0x49b40821); /* 16 */

  /* Round 2 */
  GG ( a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
  GG ( d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
  GG ( c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
  GG ( b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
  GG ( a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
  GG ( d, a, b, c, x[10], S22,  0x2441453); /* 22 */
  GG ( c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
  GG ( b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
  GG ( a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
  GG ( d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
  GG ( c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
  GG ( b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
  GG ( a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
  GG ( d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
  GG ( c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
  GG ( b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */

  /* Round 3 */
  HH ( a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
  HH ( d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
  HH ( c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
  HH ( b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
  HH ( a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
  HH ( d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
  HH ( c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
  HH ( b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
  HH ( a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
  HH ( d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
  HH ( c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
  HH ( b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
  HH ( a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
  HH ( d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
  HH ( c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
  HH ( b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */

  /* Round 4 */
  II ( a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
  II ( d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
  II ( c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
  II ( b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
  II ( a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
  II ( d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
  II ( c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
  II ( b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
  II ( a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
  II ( d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
  II ( c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
  II ( b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
  II ( a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
  II ( d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
  II ( c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
  II ( b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */

  state[0] += a;
  state[1] += b;
  state[2] += c;
  state[3] += d;

  /* Zeroize sensitive information.
   */
  MD5_memset ((POINTER)x, 0, sizeof (x));
}

/* Encodes input (UINT4) into output (unsigned char). Assumes len is
     a multiple of 4.
 */
static void Encode (
		    unsigned char *output,
		    UINT4 *input,
		    unsigned int len)
{
  unsigned int i, j;

  for (i = 0, j = 0; j < len; i++, j += 4) {
    output[j] = (unsigned char)(input[i] & 0xff);
    output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
    output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
    output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
  }
}

/* Decodes input (unsigned char) into output (UINT4). Assumes len is
     a multiple of 4.
 */
static void Decode (
		    UINT4 *output,
		    const unsigned char *input,
		    unsigned int len)
{
  unsigned int i, j;

  for (i = 0, j = 0; j < len; i++, j += 4)
    output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
      (((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
}

static void MD5_memcpy (
			POINTER output,
			POINTER input,
			unsigned int len)
{
  memcpy(output, input, len);
}

static void MD5_memset (
			POINTER output,
			int value,
			unsigned int len)
{
  memset(output, value, len);
}

#ifdef SNMP_PP_NAMESPACE
} // end of namespace Snmp_pp
#endif 

#ifdef __cplusplus
}
#endif

#endif // !defined(_USE_LIBTOMCRYPT) && !defined(_USE_OPENSSL)
